I think you can play it either way - slower as an air, or with a waltzy swing to it if you prefer. Although it's not O'Carolan, it goes nicely with Fanny Power and Planxty Irwin as a set.
If you're trying to classify it, put it in one category, then cross-ref it to the other.
Not quite sure what you mean by "played evenly on 3 beats" as it has some dotted notes in it, at least the way I play it with my pals.
And as a by the way, Ewan McVicar used this tune for his song "All the Tunes in the World" - which is a good end-of-the-night song.